Crankcase ventilating system



April 1s, 1939. G WAY 2,154,593

CRANKCASE VENTILATING SYSTEM Filed Nov. 5, 1957 -Jllll A l A TTORNE Y,

Patented Apr.. 18, 1939 STATES CRANKGASE -`TING SYSTEM Gilbert Way, Detroit, Mich., assigner to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware This invention relates to improvements in internal combustion engines.

More particularly, the invention pertains to improved internal combustion engine crank case ventilation.

One of the main objects of the invention is the provision of means for circulating through the crank case of an internal combustion engine, a current of `fresh air which is sucient in quantity to remove crankrcase lubricant diluents, such as products of combustion, water of condensation and fuel, during idling operation, and which is augmented during intermediate and high speed operations of the engine suiilciently to accomplish this result while also compensate for the introduction of the blow-by gases into the crank case during such engine operation.

Another object of the invention is the provision of improved means for applying manifold' suction to and automatically controlling the application thereof on the crank case of an internal combustion engine in order to maintain a desired flow of fresh air through the crank case during that fluctuation of the manifold suction which normally occurs, for example, in the operation of a motor vehicle.

Further objects of the invention are to provide improved valve means in a passage leading from the crank case to the fuel mixture system of an internal combustion engine for controlling the quantity of Ventilating air owing through the crank case; to provide valve means oi this character which is operable in such timed relation with respect to the carburetor throttle valve of the engine as to compensate for manifold vacuum variations which result from variations "of the throttle valve; -to provide an improved vacuum controlled valve construction which enables the throttle valve shaft of the carburetor to be used as a valve member of the Ventilating system.

An additional object ofthe invention is the provision of means for rendering the ventilation system inoperative and preventing the introduction of air and crank case diluents into the fuel mixture system of the engine during starting operation.

An illustrated embodiment of the invention is shown in the accompanying drawing, in which:

Fig. 1 is a transverse vertical sectional view of an internal combustion enginewhich is equipped with the improved crank case Ventilating system.

Fig. 2 is an enlarged, fragmentary vertical sectional view taken on the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary, mainly vertical, sectional view taken on the line 3 3 of Fig. 2..

Fig.. 4 is a fragmentary sectional view, similar to Fig. 3 but showing the parts of the structure in a changed position.

In the drawing is illustrated an embodiment of the improved crank case Ventilating system in an internal combustion engine, generally designated by the numeral It, of the type conventionally used in automotive vehicles. it comprises a crank case il, cylinders i2 having pistons I3 therein and a fuel induction system which includes inlet ports it' and an inlet manifold, generally designated by the numeral l5. Mounted on the inlet manifold l5 is a carburetor i6 having a body portion ld' in which is provided a fuel mixture passage Il which communicates with the interior of the intake manifold. An oil iller sprout Alil is mounted on the side of the crank case H and provided with an open upper extremity through which airunder atmospheric pressure is admitted to the interior of the crank case. Formed in the side of the engine opposite that on which the oil ller sprout I8 is located, is a valve chamber i9 which is com- 2 5 municatively connected with the crank case by a passage 20. The valve chamber I9 is provided with a removable closure 2l having an aperture therein through which a conduit 22 extends.

The lower end of the conduit 22, as viewed in Fig.

1, communicates with the interior of the valve chamber i9 and with the interior of the crank case through the passage 20. The upper end of the conduit 22 is communicatively connected, by

a tting 23, with a passage 2'formedin the 35 body portion IS'of the carburetor and leading downwardly, at an inclination, as shown in Fig. 2, to and opening into the fuel mixture passage il. The carburetor body portion I6' is also provided vvith a substantially horizontal bore 2d 40 which intersects the passage 24 and in which is journalled a throttle valve shaft 26 having a throttle blade 21 mounted thereon and disposed in the fuel mixture passage il at a location above the outlet end portion 28 of the passage 2li. That 45 portion of the throttle valve shaft 26 which extends through the common section of the passage 24 and bore 25 is so notched, as illustrated at 28 in Figs. 3 and 4, as to serve as a valve member for controlling the flow of air and with- 5@ drawn crank case diluents from the crank case il The throttle valve shaft 26 has an external end portion on which is xed a lever 29 that is operatively connected with an accelerator rod or other suitable control rod 30.. The throttle value The engine 10 simultaneously operated by the lever 29 and rod 30 during controlling of the speed of operation of the engine.

The valve section 28 of the throttle valve 26 is so constructed and arranged as to accommodate only a minimum flow of air and crank case diluents from the crank case when the throttle valve is positioned to establish idling operation of the engine. When the throttle valve is moved from its idling position, illustrated in Fig. 3, to its substantially full open position shown in Fig. 4, the valve section 28' of the throttle shaft 26 is turned to the position shown in Fig. 4 at which it accommodates the maximum flow of air and crank case diluents from the crank case to the fuel induction system. The amount of air and crank case diluents withdrawn from the crank case is gradually increased as the throttle is moved from its idling position to its wide open position.

Withdrawal of air and crank case diluents from the crank case is induced by the normal carburetor suction, as well as by the ejector effect which results from the inclination of thel passage 24, shown in Fig. 2, with respect to the axis of the fuel mixture passage I1 at the location Where the passage 24 opens into the'passage l1.

During operation of the engine at idling speed, the valve provided by the section 28' of the throttle shaft 26 permits the withdrawal of suflcient air and crank case diluents from the crank case of the engine to prevent the accumulation of such diluents therein. During such operation of the engine the throttle valve is substantially closed and a relatively high vacuum is available for the promotion of an air circulation through the crank case. As the throttle valve is opened to increase the engine speed, the vacuum is somewhat reduced and at high speed operation of the engine there is an additional amount of fuel flowing by the piston into the crank case. The opening of the valve simultaneously with opening of the throttle compensates for this additional blow-by gas as Well as for reductions in the vacuum of the fuel induction system. By virtue of this construction, ample circulation of air through the crank case and withdrawal of diluents therefrom is provided during idling operation and excessive removal of lubricant vapor from the crank case is avoided while during high speed operation provision is made to accommodate the Withdrawal of the blow-by gases from the crank case which are incident to fast operation of the engine.

In order to prevent disturbing of a predetermined fuel mixture ratio of the fuel mixture supplied to the engine for starting purposes, a valve 3l may be provided in the conduit 22 by which the Ventilating system may be rendered inoperative during the starting operation. The' valve 3| is preferably controlled by a solenoid 32 which is electrically connected in series with the switch 33 of the engine starting system. When the switch 33 of the starting system is closed in a conventional manner, by depression, for example, of a starter pedal 34, the valve 33 is closed so as to prevent the application of carburetor suction on the crank case. After the engine is started 21 and the valve section 28 of the shaft 28 are and the pedal 3411s released, the valve 3l is returned to its open position, preferably by a spring (not shown) in accordance with the usual practice in solenoid valve operation. This valve action is beneficial in many installations but is not essential in all cases.

Although but one specific embodiment of the invention is herein shown and described, it will be understood that various changes in the size, shape and arrangement of parts may be made without departing from the spirit of my invention.

What I claim is:

1. In an internal combustion engine including a crank case having Ventilating air inlet and outlet openings and having fuel induction and engine starting systems; a control for said fuel induction system, a crank case Ventilating system including means communicating with said outlet opening and with said fuel induction system at a location in the latter of subatmospheric pressure for inducing the flow of a current of air through said crank case and for withdrawing diluents therefrom, variable valve mechanism in said means for controlling the quantity of air and diluents withdrawn from said crank case, apparatus for regulating said valve mechanism in accordance with the operation of said fuel induction system control, and mechanism responsive to actuation of said engine starting system for discontinuing the flow of air and fuel vapor through said means when said starting system is operative.

2. In an internal combustion engine including` a crank case having Ventilating air inlet and outlet openings and having fuel induction and electric engine starting systems; a control for said fuel induction system, a crank case Ventilating system including means communicating with said outlet opening and with said fuel induction system at a location in the latter of subatmospheric pressure for inducing the flow of a current of air through said crank case and for withdrawing diluents therefrom, variable valve mechanism in said means for controlling the quantity of air and diluents withdrawn from said crank case, apparatus for regulating said valve mechanism in accordance with the operation of said fuel induction system control, and Valve mechanism in said means including a solenoid actuating member electrically connected With said engine starting system and energizable simultaneously therewith for discontinuing the flow of air and crank case diluents through said means during engine start# ing operations.

3. In an internal combustion engine including a vcrank case having Ventilating air inlet and outlet openings and having fuel induction and engine starting systems; a crank case Ventilating system including means communicating with said outlet opening and with said fuel induction system 1.

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